Apparatus for drying foundry molds



Naw. 9, w48. c. A. BARNETT ETAI. 2&4539400 APPARATUS FOR bRYING FOUNDRY MOLDS Filed July 13, 1943 5 Sheets-Sheet l T- INVENTORS IE 3 CHARLES AARNETTand JOSEPH M. BEYVL ATTQRNEYS OV- 9 w48- c. A. BARNETT Erm.,

APPARATUS FOR DRYING FOUNDRY MOLDS Filed July 13, 1943 5 Shets-Sheet 2 WJUIHM .vm Nm H C C c @X1 l l Aww, A mm X l Nm w m94.. I* 1% n Ow 1 WWK w 5. 8 on mw mw nw INVEN'I" ORS CHARLES AJBARNETTund JOSEPH MBEYVL ATTORNEYS NOV- 9 1948- c. A. BARNETT E'rAL.

APPARATUS FOR DRYING FOUNDRY MOLDS s sheets-sheet 's Filed July 13, 1943 INVENTORS CHARLES AARNETTomd JOSEPH MBEYVL M/ U ATTORNEYS by either one of two general methods.

these methods is the surface or skin drying proc-W tioning process and and economically ?atenteci Nov.y 9, .i948 I Niro ES l

APPARATUS FOR DRYliNGrA FOUNDRY MOLDS Charles A. Barnett and Joseph M. Beyvl, Cleveland, h10, asslgnors armeni;1l Company, Clevel of() o to The Foundry Equipand, 6h10, a corporation Application July 13, 1943, Serial No. 494,458 e claims'. (ci. 22-8'1) The present invention relates to apparatus for conditioning foundry molds, and the like and has particular reference to the backing and drying of the green' sand in such molds in a zone adjacent the mold-forming surface thereof.

In metal founding practice, after the green sand is so patterned or formed in the mold body or iiask (the latter of course including copes and drags, if need be), the sand must be so treated or conditioned as tol be enabled to come in contact with the molten metal without causing certain disadvantageous results. Green sand molds have therefore previously been ,treated or condgtioned ne of ess whereby heat is applied to the mold-forming surface of the sand, such as by a gas torch played over such surface, or byheat radiated from a The other gas, oil, electrical or solid fuel burner. method generally employed to condition green lsand molds involves the subjecting of the entire mold body to a baking or heat soaking operation in a drying oven. It will readily be appreciated that the first of these two general methods of treatment is subject to the disadvantage of uneven application 'of heat to the mold-forming surface and the ineilicient' and uneconomical transmission of heat; the second general process having the disadvantage of requiring relatively long periods of time for effecting the penetration of the drying or baking heat throughout the entire mass of the mold body, not to mention the excessive amount ofheat required.

In the co-pending U. S. patent application of C. A. Barnett, co-applicant herein, Serial No.

408,063, filed August 23, 1941,' now Patent 2.385 962, there has been disclosed a mold condiapparatus whereinjthe mold body, containing the green sand, is placed upon a continuously moving conveyor and subjected to a blast of heated'air which is so directed as to impinge uniformly upon the sand mold-forming surface, producing rapid and uniform drying of such surface throughout an even depth zone. However, it is not feasible or practical to employ a continuous conveyorfor all types and sizes of foundry molds. Either th space required by such a conveyor and its associated housing and forced air heating apparatus would be toc large when considered in proportion with the number or sizes of the molds conditioned, or the cost vof such an apparatuswould be out of proportion. Our present invention, therefore, is directed to the provision of and drying sand and weight as to an apparatus for conditioning molds which are of such a size prevent them from practically being transported upon a continuous conveyor type of drying oven, and wherein the mold body itself is utilized as part of an enclosing housing or drying oven during the green vention may be used.

f means hereinafter sand drying and baking operation. Briefly outlined, our invention comprises an open-topped housing which is adapted to support the mold body upon its top edge, together with a forced air heating source located adjacent the opentopped housing and adapted to deliver a .mass of heated air through a plurality of appropriately directed nozzles surface.

Additional objects and advantages of the invention shall become apparent as the following description proceeds. I,

To ,the accomplishment of the foregoing and related ends, said invention, then, consists of the fully described and particularly pointed out in the claims. Y

The annexed drawings and thefollowing description set forth in embodying the invention. such disclosed means constituting, however, but one of various mechanical forms in vwhich the principle oi' the inagainst the mold-forming sand In said annexed drawingsz` Fig. 1 is a top plan view of. a-single mold drying apparatus embodying the principle. of our invention:

Fig. 2 is an elevational view, partially in section. ci' the apparatus shown in Fig. 1;

Fig. 3 is an enlarged, sectionaldetail of the sand seal around-the top edge ofthe supporting housing of the apparatus shown in Figs. I and 2;

Fig. 4 is a top plan view of a multiplemold drying apparatus embodying the principle of our invention; Y y

Fig. 5 is a vertical sectional view taken substantially along the line 5 5 and in the direction of the arrows, in Fig.. 4;

Fig. 6is a vertical sectional '.view stantially along line 6-6 of Fig. 4;'

Fig. 7 is a top plan'view vofa multiple mold drying apparatus, whose constructionhas been so modified as to accommodate the interior part of a mold body or core, and embodying the principle of our invention;

Fig. 8 is a vertical sectional view taken substantially alongl the line 8 8 of Fig. 7; and

Fig. 9 is a vertical sectional view taken substantially along line 9,-9 of Fig. 7.

Now referring more particularly vto Figs, land 2, the apparatus shown therein comprises an taken subopen-topped housing indicated generally at i with a foundry mold body supported upon the top side thereof in inverted position. A heater 3, consisting of a heat transfer chamber and a burner for gas, oil or solid fuel (steam or elecl detail certain mechanism enclosed by the housing I and the inverted mold body 2. A return or reclrculating duct 6 leadsfrom interior of the housing I back to the intake side of the heater 3.

This structure is operative with or without an outside vent in the system for the recirculated air. There is adequate air in the system to absorb the moisture in one or a few molds. The absorptive capacity of the air is muchgreater than required and is not approached in normal operation, the limiting i actor being the expansion of the air due to moisture absorption, and with some types of heaters, the addition of medium such as combustion products. This latter limiting factor is not reached in drying the single mold and when the mold is dried and removed, any pressure due to expansion is relieved and fresh air is admitted into the system between the time of removal of the dried mold and the placing oi' a new mold on the open top housing. thus venting the system.

If desired, the mold may be vented for bleeding out any air or excess products, for example, as pointed out in my copending application, Serial No. 494.756, led July 15, 1943, now Patent 2,417,673, granted March 18. 1947, by providing a suitable venting duct in the return duct 6. The venting duct may be utilized for withdrawing 'the excess'air from the interior of the mold.

The housing I consists of the bottom wall 1 and the vertical side walls 8 and 9. These walls are primarily fabricated of brick, concrete or other equivalent insulating material in order t minimize heat loss. Supporting piers I0, consisting of vertically mounted I-beams, are located at each of the four corners of the rectangular shaped housing I, and in addition to reenforcing the side walls 8 and 9, also provide bearing supports for the weight of the mold body 2. The latter comprises the outer casing or flask II and the interior filling of mold sand which forms the mold cavity indicated at I2.

A plurality of nozzles I3 and I4 are located on the outlet end of the conduit 5, and as shown in Fig. 2, are directed both upwardly and outwardly toward the surface of the mold cavity I2 whereby the mass of heated air supplied from the heater 3 and blower 4 is propelled or forcibly projected substantially at right angles all over, and' uniformly against, the interior surface of the sand mold, drying and baking the latter to a uniform depth adjacent such mold-forming surface. The arrows in Fig. 2 substantially indicate the manner in which the heated air streams from the nozzles I3 and I4 impinges against the-surface of the mold cavity I2. After such impingexnent and transfer of the majority of the sensible heat from such impinging air streams to the surface and adjacent surface zone of the sand in the mold body 2, the body of air then passes into the outlet openings I in therecirculating duct 6, whence the cycle of reheating in the heater 3. blower 4 (driven by the drive motor I6) through the delivery conduit 5 to the housing I, continues. As best shown in Fig. 3, the mold body 2 is mounted upon the top edge of the housing I in such manner as to provide an effective air seal. preventing escape of the heated air to the atmosphere. This sealing means comprises a channel I1 located around the top sides of the housing walls B and 9 and slightly wider than the bottom marginal flange I8 on the flask II. The channel I1 is nlled with sand which contacts the bottom side of the flange I8 and forms an effective air seal between the channel I1 and danse I8.

continuous conveyor.

The above described apparatus has been found to be extremely eilicient in solving the problem of satisfactorily and rapidly drying green sand inifoundry molds which, although they can be handled or transported from one place to the other by means of overhead cranes or hoists, cannot be practically or economically handled on a vention is particularly well adapted to the drying of foundry molds of about to 100 square feet cross sectional dimensions. From the foregoing description. it will be readily appreciated that the apparatus embodying our invention not only overcomes the problem of conveying molds oi this size for the purpose of eilciently projecting a uniformly drying mass of heated air against their mold cavities, but also eliminates thek necessity of a relatively large and cumbersome enclosing housing, inasmuch as the mold body itself is so combined with the supporting housing I as to form a complete and enclosed space for the reception and recirculation of the drying air mass.

In Figs. 4, 5 and, we have illustrated the principle of our invention as applied to a multiple mold drying apparatus. The latter com-- prises an elongated housing indicated generally at 20 having the vertical side walls 2l and the vertical end walls 22, enclosed on the bottom by the bottom wall 23. The elongated housing 20 is divided into a series of four adjacent' compartments by means of the transverse walls 2,4. The walls 2|, ,22, 23 and 24 are4 of course fabricated from an insulating material.

Supporting piers 25, consisting of vertical L-beams, are located at each of the four corners of the four compartments in the housing 20 and have bearing plates 26 positioned upon their top ends to receive the inverted mold bodies 30. Sand seals, comprising the channels 21 and 28 around the upper perimeter of each one ofl the compartments in the housing 20, and lled with a body of sand adapted to contact with the marginal flanges 29 on the mold bodies 30, are provided for the same purpose just as described in connection with the apparatus of Figs. 1, 2 and 3. The mold cavity 3l and mold body 30 thus forms a continuationof or portion of the interior space in each one of the compartments in the housing 20.

A heater 32,. connected to the blower 33, the latter being driven by the drive motor 34, provides a quantity of heated air or similar gaseous medium which is delivered through the conduit 33 extending substantially the entire length of the housing 20. The delivery conduit 35 has a 'series of outlet manifolds 33 to which the air stream directing nozzles 31 are connected, at each l.one of the four compartments in theA housing 23. Openingsl are provided between the delivery conduit 33 and each one of the compartments, such openings being adapted to be opened or closed by means of the pivotally mounted damper 38. The damper 3l is in turn operated by means of the damper rod. extending out to the exterior of the side wall 2l of the housing 20.

Return conduits Il extend throughout the length of the housing 20 and are located adjacent each side of the delivery conduit 35. The recirculating or return conduits I0 are joined at the right hand end of the housing 2l by means' of the conduit 4I to the conduit I2 returning to the heater l2. The conduits III have openings located in each one of the four compartments in the 'housing 23 which are adapted to be opened or Our above described inclosed by means of the slidable covers 43 which in turn are manipulated by means of the rods 44 extending through the walls 2l ofthe housing 20.

From the foregoing description of the apparatus of Figs. 4. 5 and 6, it will be seen that the mold bodies are subjected to the same manner of drying treatment as in the case of the apparatus of Figs. 1 and 2 and that the same advantages, except for an increased production capacity, ensue. In addition, the heated air circulating system may be continuously operated in the apparaus of Figs. 4, 5 and 6, without any material loss -of heated air to the atmosphere, and without interruption, as individual mold bodies are placed upon and removed from the supporting housing As completely dried molds are removed from their positions on the housing 20, and new onesy containing green sand, installed in their place, it is merey necessary to close the dampers 39 and outlet opening covers 43` in the particular compartment in which such changeover is taking place.

In Fjgs. 7, 8 and 9, we have shown the apparatus of our invention, as modified to accommodate the drying treatment of mold parts which do not have an enclosing housing, such as a ask, and do not present any substantial size interior cavities. In other words, the apparatus shown in Figs. 7, 8 and 9 is adapted to accommodate what is commonly called the core in foundry praetice, and which technically speaking, is the male part of the entire mold body when nally assembled frthe casting operation.

In the apparatus of Figs. 7, 8 and 9, there are again the heater 50, the blower 5I and the'delivery conduit 52 extending the length of the elongated housing 53. The housing 53 is composed of the bottom wall 54, and the side and end walls 55 and 56, the latter being relatively higher than was found to be the case in the apparatus of Figs. 4, 5 and 6. The housing 53 is divided into individual compartments by means of the transverse walls 51. A plurality of air stream directing nozzles 58 are located in the delivery conduit 52 in each of the compartments of the housing 53 and are adapted to direct the forcibly projected mass of incoming air upwardly and around the exterior surface of the core 59, substantially as indicated by the arrows as shown rin Figs. 8 and 9. In addition, there are upper manifolds 00 having outlet nozzles 6I, and connected by means of the riser ducts 62 to the main delivery conduit 52, in each one of the compartments in the housing 53. The cores 59 are connected to the channel beams 63 by means of the suspension pins 64. The channel beams` 63 are in turn supported upon the compression springs 65 adjacent their outer ends which in turn bear upon the I-beams 66 located adjacent the top and inside the side walls 55 of the housing 53, The top of eachof the compartments in the housing 53 is closedby a pair of hinged-covers 61, carrying the counterweights 68. The covers 61 have a sealing strip 69, made of asbestos tape or the like, located along their edges adjacent the supporting channels 63, and adapted to form a sealing engagement therewith when the covers are closed and the channels 63 in place. A hinged baille plate 'I0 is mounted upon one of the covers 61, beingr hinged at a point along the outer edge of the latter and is adapted to be drawn over into place when the individual mold core treating compartment is empty, i. e. when the supporting beams 63 are not present.

Return or recirculating ducts H extend on each side of the delivery duct 52 and throughout the length of the housing 53. The return ducts 1l are likewise joined by the transverse duct 'l2 leading to the return intake duct 'I3 of the heater 50. The inlet openings of the return ducts 'Il are located in the horizontal manifold 'I4 along each side wall 55 of tne housing 53 being connected to the return conduit 1I by means of the risers 15, in substantially the same manner and extent as the delivery manifolds 60 and risers 62.

Other modes of applying the principle of our invention may be employed instead of the one explained, change being made as regards the mechanism herein disclosed, provided the means stated by any of the following claims or the equivalent of such stated means be employed.

We therefore particularly point out and distinctly claim as our invention:

1.` Apparatus for drying foundry mold bodies of generally concave form, enclosed in a peripheral frame, comprising an open-top housing having an upper marginal edge of substantially the same shape and dimensions as the outer marginal edge of the mold body to be dried and adapted to support the same in inverted position thereon with the mold cavity and parting surface of the mold body exposed in the housing, a-heater, an

inlet conduit for heated air leading from theV heater Into the housinga plurality of nozzles extending upwardly beyond the .housing and adapted tcdirect heated air from the conduit and discharge the air upwardly and outwardly at a plurality of separate locations abo-ve the level'of the marginal edge of the housing so as to cause such air to impinge in separate spaced streams against the concave surface of the mold body, an exhaust conduit leading from the housing to the heater and opening into the housing below the level of said upper marginal edge, air circulating means to withdraw air from the housing, through said conduit, and force said air through the heater and back into the housing through the inlet conduit and means sealing the joint between the frame of the mold body and the upper marginal edge of the housing.

2. An apparatus according to claim 1 charac terized further in that said sealing means cornprise an upwardly open channel forming the upper marginal edge of the housing and a body of loose sand substantially filling said channel and adapted to engage the bottom margin of the frame when the mold is supported on the housing.

CHARLES A. BARNETT. JOSEPH M. BEYVL..

REFERENCES CITED The following references are of record in the le of this patent:

UNI'TED STATES PATENTS Number Name Date 526,101 Drake n'. Sept. 18, 1894 530,641 Hansen Dec. 11, 1894 1,057,905 Widekind Apr. 1, 1913 1,167,889 `Davis Jan. 11, 1916 1,373,688 I Vergniaud Apr. 5, 1921 1,749,448 Sculthorpe Mar. 4, 1930 v 1,923,940 Ludwig Aug. 22, 193.3 2,187,161 Kulke Jan. 16. 1940 2,311,309 Bergstrom Feb. 16, 1943 FOREIGN PATENTS Number Country Date 123,769 Great Britain Oct. 2, 1919 

